The six males and three females were rescued from various sites along the east coast earlier this year seriously underweight, or suffering from wounds or lungworm.

The seals started in the intensive care cubicles at the centre, where they are hand-fed, before being moved into the large pools as they began self-feeding and gaining weight until they reached conditions for release.

They were released on Friday, May 12.

Alison Charles, manager of the RSPCA’s East Winch Wildlife Centre, said: “We are so happy to see these gorgeous creatures returning to the wild after having such difficult starts in life.

“We always release seals into the River Nene at Sutton Bridge, in Lincolnshire, on a receding tide. This takes them out to the exposed sandbanks in the Wash where there are other wild seals.

The RSPCA uses this route after data from its satellite tracking study of 2004 showed that this release method is ideal for the seals and gives them a good start to life back out at sea.

If you have concerns about an animal, call the RSPCA’s emergency line on 0300 123 9999

RSPCA advice on seals

The RSPCA gives a range of advice to people who might come across injured seals along the Norfolk or Suffolk coast:

• Please do not touch the seal. They can give a nasty bite, which will become infected by the bacteria that live in a seal’s mouth.

• Do not allow dogs or other animals to harass a seal – it could be scared back into the water and washed out to sea by strong currents.

• Never put a seal pup back in the sea as it may get into difficulty. Many pups are suffering from pneumonia and the last thing they want or need is to go back into the water. Seals tend to get themselves as far away from the water as they can when they are sick and the RSPCA has found them some distance inland.